diff --git a/var/spack/repos/builtin/packages/ncl/package.py b/var/spack/repos/builtin/packages/ncl/package.py
index 651911ec7f2..1d84b1435be 100644
--- a/var/spack/repos/builtin/packages/ncl/package.py
+++ b/var/spack/repos/builtin/packages/ncl/package.py
@@ -40,7 +40,7 @@ class Ncl(Package):
     # Non-optional dependencies according to the manual:
     depends_on('jpeg')
     depends_on('netcdf')
-    depends_on('cairo+X')
+    depends_on('cairo+X+pdf')
 
     # Extra dependencies that may be missing from build system:
     depends_on('bison', type='build')